Cooling System for an Electric Device and Electric Motor With the Cooling System

Abstract

A cooling system for an electric device, particularly an electric motor, includes a housing, a rotor enclosed in the housing and a cooling circuit having a first part for transporting cooling fluid on the circumferential surface of the rotor from the first side to the second side and a second part for transporting the cooling fluid back to the first side or vice versa. The second part is located at least partially inside the housing and has a larger distance to the rotation axis than the first part.

What is claimed is: 
     
         1 . A cooling system for an electric device, comprising:
 a housing;   a rotor enclosed in the housing, the rotor comprising a rotor body that rotates around a rotation axis and has an outer circumferential surface,   wherein the rotor body has a first side and an opposing second side, the first side and the opposing second side being spaced apart from each other along the rotation axis; and   a cooling circuit having a first part for transporting cooling fluid on the outer circumferential surface of the rotor from the first side to the second side and a second part for transporting the cooling fluid back to the first side, or vice versa,   wherein the second part is located at least partially inside the housing and has a larger distance to the rotation axis than the first part.   
     
     
         2 . The cooling system according to  claim 1 , wherein the cooling circuit is driven by rotation of the rotor. 
     
     
         3 . The cooling system according to  claim 1 , wherein
 the outer circumferential surface of the rotor is provided with at least one spiral rib extending from the first side of the rotor body to the second side of the rotor body.   
     
     
         4 . The cooling system according to  claim 3 , wherein
 the outer circumferential surface of the rotor body is provided with two or more spiral ribs, extending parallel to each other and being spaced apart, in a circumferential direction.   
     
     
         5 . The cooling system according to  claim 1 , wherein
 the outer circumferential surface of the rotor is provided with at least one spiral groove extending from the first side of the rotor body to the second side of the rotor body.   
     
     
         6 . The cooling system according to  claim 5 , wherein
 the outer circumferential surface of the rotor body is provided with two or more spiral grooves, extending parallel to each other and being spaced apart in a circumferential direction.   
     
     
         7 . The cooling system according to  claim 1 , wherein
 the housing further encloses a stator, the stator surrounding the rotor at least in part in a circumferential direction.   
     
     
         8 . The cooling system according to  claim 7 , wherein
 the stator surrounds the rotor completely in the circumferential direction.   
     
     
         9 . The cooling system according to  claim 7 , wherein
 the stator comprises stator holes extending from a first side of the housing to a second side of the housing, and   the second part of the cooling circuit extends through the stator holes.   
     
     
         10 . The cooling system according to  claim 7 , wherein
 the stator has an inner surface facing the outer circumferential surface of the rotor, and   the inner surface of the stator is provided with at least one spiral rib and/or at least one spiral groove.   
     
     
         11 . The cooling system according to  claim 10 , wherein
 the inner surface of the stator is provided with several spiral ribs and/or grooves extending parallel to each other.   
     
     
         12 . The cooling system according to  claim 1 , wherein
 the cooling circuit is located inside the housing.   
     
     
         13 . The cooling system according to  claim 12 , wherein
 the cooling circuit is located completely inside the housing.   
     
     
         14 . The cooling system according to  claim 1 , wherein
 the cooling circuit further comprises an external reservoir and/or an external heat exchanger, and   the cooling circuit is connected to the external reservoir and/or the external heat exchanger through at least one inlet and/or outlet hole in the housing.   
     
     
         15 . The cooling system according to  claim 14 , wherein
 the cooling circuit is connected to the external reservoir and/or the external heat exchanger through the at least one inlet and/or outlet hole located in a first sidewall of the housing.   
     
     
         16 . An electric motor, comprising:
 a cooling system according to  claim 1 , wherein   the electric motor comprises the housing, the stator and the rotor enclosed in the housing.